There was actually a British spoof version called 'Barry Trotter' by Michael Gerber that we had when we were younger. I'm actually reading a spoof of The Hobbit, entitled 'The Soddit' by A.R.R.R Roberts.

I like the one where Harry goes evil, and the one where Hogwarts drafts six asian wizards from the Chinese school to save the day because all the honkey coloured (and two black probably) wizards were too incompetant to defeat the great evil.